MH17: footage believed to show a Buk missile system being driven in Torez, Ukraine. Photograph: EMPR/Barcroft Media

In the aftermath of an event as tragically uncertain as the MH17 plane disaster, amid claim and counterclaim about who was responsible, it becomes ever more important for news organisations to verify the validity of material on social media.

This is where social news agency Storyful and its Open Newsroom come into their own. The Dublin-based company – acquired by News Corp for €18m in December 2013 – specialises in finding and verifying news content on social media. Open Newsroom, which Storyful launched on Google+ in June 2013, is “a real-time community of news professionals” whose objective is to “debunk, fact-check, clarify, credit and source” information around big news stories.

Last week, amid a flood of unverified information following the shooting down of Malaysia Airlines Flight MH17 in eastern Ukraine, Open Newsroom confirmed members of the Donetsk People’s Republic separatist militia “at the very least” appeared to have access to an anti-aircraft missile system capable of an attack like the one carried out on the plane.

“There are now four pieces of content – three pieces of video and one image – which, in the case of three, conclusively show a Buk [surface-to-air] missile within rebel-held territory and in the case of the fourth, almost definitely in their territory,” says Storyful executive editor David Clinch. “Of those four pieces, individual groups or companies probably verified in or around the same time one or another of them.”

Open Newsroom verified three pieces of content and is investigating the fourth, thanks to its 900-strong network of journalists and experts. “It’s not trivial stuff,” Clinch says. “The US is out there saying, ‘We are looking at pieces of social media content [in its own investigation].’”

Storyful’s Open Newsroom is the latest high-profile experiment in open journalism, sharing early information with readers who are invited to contribute to the reporting process. The concept is not particularly new, dating back to the late 1990s, but it has faced resistance from journalists who are used to being tight-lipped about scoops.

There has also been a more general reluctance among journalists and other media professionals to recognise the worth of user-generated content, on grounds of both quality and trust. Clinch, who previously pioneered the use of social media for newsgathering at CNN, believes that journalism – outside of certain truly exclusive stories – can only benefit from the open approach. “The end product is better because of that [initial] discussion being in public,” he says. This, naturally, includes Storyful’s own end product, with the company providing “verified socially-sourced content” for media clients.

Mark Little, the former RTE journalist who founded Storyful and is now chief executive, says: “Open Newsroom provides a transparency which traditional journalism has lacked. Every editorial decision leaves a trail of verification and discussion. Every story evolves with the speed of fact, not commentary or speculation.”

In the case of MH17, Storyful published a blog outlining the key steps it took in verifying the information it gathered from social media, including searching through Twitter posts associated with the Donetsk People’s Republic – many of them since deleted – looking for historical references to surface-to-air missile systems, geolocating YouTube videos purporting to show the missile system in eastern Ukraine prior to the crash and verifying videos from the crash site. But only Storyful clients had access to all of the company’s “forensic end-point verification”, including contact numbers and emails.

This may, on the face of it, seem contrary to the principles of open journalism. But Clinch argues that journalism needs to be sustainable to survive. “We’re not in the business of saying, ‘Our goal is to do everything for free and somebody else should pay for it. What we want to be able to do is have a sustainable new business, which incorporates a public and ‘noble’ element.”

It is an approach that appears to be working. The company last week announced the launch of version 2.0 of its newswire dashboard while expanding its global staff, with Mandy Jenkins, formerly of the Huffington Post, joining as Open Newsroom editor. Storyful continues to develop its work with brands and agencies, as well as expanding its rights management business for user-generated video.

In April the company launched Facebook Newswire, a partnership designed to make it easier for journalists to find newsworthy content on the social media platform. Clinch says the early signs are that it is a success, with publishers regularly repurposing news content they find on the site. The goal now, he adds, is to make the Newswire more of a “curated environment”, where journalists can search for stories by subject or keyword.

This, of course, is an approach that fits well with Storyful’s vision of open journalism and social newsgathering. But, as the old, siloed view of journalism – web/TV, traditional/social, closed/open – fades, Clinch says he sees widespread evidence that traditional media operators are also starting to embrace these new models.

“For sustainable journalism – particularly digital-first journalism – you cannot just rely on sources of information or video content that exist traditionally,” Clinch says. “If that is the only place you are looking you are missing huge amounts.”